1. Field of the Invention
This invention relates in general to electrophotographic reproduction and more in particular to an electrophotographic reproduction method and apparatus which is capable of making two-dimensional copies of a three-dimensional object.
2. Description of the Prior Art
Prior art electrophotographic copying machines are usually built to make two-dimensional copies from a two-dimensional original such as a book or sheet of paper. In such prior art copying machines, in-focus conditions are satisfied when a two-dimensional original is properly placed on the top surface of the contact glass plate. However, since the optical system of the prior art copying machines usually has a limited or shallow field of depth, they are not suited for making two-dimensional copies of a three-dimensional object, i.e., making a copy of the projected image viewed in one direction of a three-dimensional object on a sheet of copy paper.
It has often been required to make two-dimensional copies of a three-dimensional object. For example, in a surgical operation, autopsy and the like, internal organs removed from the patient or dead body are preserved as specimens in spirits at least partly. However, more often than not, photographic pictures of the removed organs are taken with the use of a special photographic device for internal organs so that the pictures may be filed together with related medical certificates or reports.
It is true that such a special photographic device is equipped with means for adjusting the field of depth of its lens in multiple steps by maneuvering its optical system. However, such means for adjusting the field of depth is rather complicated in structure and thus it tends to be expensive as well as unreliable. Moreover, such a prior art device requires a relatively long period of time for processing such as developing and printing, and its result cannot be checked on the spot. If a required portion has been found to be insufficiently photographed, rephotographing can be made only with difficulty and insufficiency. In certain circumstances, rephotographing is impossible or meaningless because of the decay or disposal of the removed organ in question.
It should further be noted that the image on a photographic picture is usually reduced in size and it may be too small to examine certain parts of the photographed object. Besides, difficulties are often encountered in recognizing the actual size of the photographed object. Such a picture is disadvantageous because notes cannot be written thereon. Another disadvantage is that its usage is rather limited and therefore there are many occasions where such a special photographic device is not applicable, though it is an expensive device.